For simplicity, reference will be particularly made herein, without limitation, to a coating machine for applying/spreading a layer of glue to a threaded shaft of a screw. Additionally, the present disclosure may also relate to a machine for applying/spreading such product to a general cylindrical element other than a screw shaft.
Screws or other equivalent threaded members having a threaded portion entirely or partially coated with fixing/sealing and/or self-locking materials are known in the art. Their purpose is to prevent properly tightened screws from unscrewing/loosening due to vibrations, shocks, thermal stresses and the like.
The need to be fulfilled is to spread/apply a layer of a suitable material over the entire circumference of at least one preset axial length of a screw. In view of fulfilling such requirement, various types of machines are known to be suitable for this purpose, which are generally known in the art as coating machines. These coating machines are designed to deposit a suitable fixing material on the threaded shafts of screws as they receive them from a vibrating feeder.
It shall be noted in this respect that there is a great variety of screws to be treated, not only in terms of possible sizes, but also and especially in terms of their possible configurations. An example of this variety of screws is screws that, while being of the same type, have different head heights.
In order to ensure treatment of screws of different types and/or sizes, these coating machines are equipped with special adjustment means, which may be used to adjust the operating units or members according to the particular screw to be treated.
In prior art coating machines, the adjustment of operating units and members has been found to be generally troublesome, whereby this operation is rather complex.
It shall be further noted that the adjustment of the coating machine to fit the physical characteristics of a particular screw adversely affects the possibility of feeding the screw through a vibrating feeder. When changing the position of the various members of the coating machine, including the inlet channel for the screws to be treated, the outlet of the vibrating feeder will become offset from such inlet channel for the screws to be treated, which will prevent the use of the machine without solving this problem.
In order to obviate the above drawback, a solution to the prior art coating machines consists in displacing/repositioning the coating machine with respect to the vibrating feeder and to move the outlet of the vibrating feeder back to alignment with the above mentioned screw inlet channel of the coating machine.
It shall be noted here that in most cases, the vibrating feeder is a stand-alone part, separate from the coating machine. Therefore, in spite of the possibility of providing an integrating unit comprising both the vibrating feeder and the coating machine, the need that is felt in the art is to use standalone coating machines to be combined with a standard vibrating feeder selected from those commercially available.
The present disclosure is based on the problem of conceiving and providing a machine for applying a coating to screws, namely a coating machine as defined above, that has such structural and functional characteristics as to fulfill the above needs, while obviating the above prior art drawbacks.
This problem is solved by a machine for applying a coating to screws, particularly a coating machine, as defined in one or more of the claims of the present application.